For determining acceleration use is made of accelerometers. The accelerometers are considered to measure so-called apparent acceleration. Owing to the above, while tilting their axes of sensitivity from the axis along which the measurement of acceleration is made (in particular, a horizontal or vertical axis) there occur major errors being impermissible. Said errors are caused by the action of cross-axis accelerations (in particular, vertical acceleration when measuring horizontal acceleration or horizontal acceleration when measuring vertical acceleration).
For decreasing said errors, said accelerometers are located on a complicated, expensive, heavy and bulky stabilized (in a horizontal plane) gyro platform. In addition to that, said gyro platform possesses other considerable drawbacks and shortcomings as well: a long initial alignment (for an accurate alignment tens of minutes are required), the necessity of using very precise gyroscopes, considerable dependence on the action of vertical acceleration, vibrations and others. However, it is impossible to implement absolutely precise leveling of said platform. Practically always there is its tilting relative to a horizontal plane. And although said tilting is minor, its harmful influence is considered to be rather noticeable, since the output signal from the accelerometers is usually integrated.
Let's show the above by way of examples.
Let some flying vehicle be moving at constant speed at constant altitude and let the platform be tilted only by a constant angle (not only by value but also by sign), it being equal to 1′.
In this case, due to integration of the apparent acceleration when determining horizontal distance or the altitude of a flight, as well as the depth of sinking in water, there occurs an accumulation error being approximately equal to 300 m per every minute of work, which is unacceptable.
For eliminating said error the authors have developed devices [1], [2], and [3]. Moreover, for the operation of said devices no gyro platform is required. They can be located directly on the body of
a moving object, which makes the constructions much simpler, lighter, less expensive, and smaller in size.
However, both in said accelerometer and in said devices [1], [2], [3] there occurs an error caused by the action of centrifugal (centripetal) accelerations. When the moving object is being rotating, by itself or around any instantaneous center of the rotation, above error can be intolerably big.
For eliminating said error the use of azimuth stabilization is required, which makes the construction considerably more complicated, and thus, increases its weight, cost and sizes.
Moreover, the azimuth stabilization does not fulfill its function even in a straight and level flight, it being because of centrifugal (centripetal) accelerations occurring due to the Earth's rotation and the rotation of a flying vehicle around the Earth's center, when moving in the Earth's sphere. This harmful influence is especially noticeable when determining the altitude of a flight.
Let's show the above by way of example.
Let said flying vehicle be moving along the Earth's equator in an east direction at constant altitude at constant speed being approximately equal to 2000 km/hr. In this case, even with the strict location of the axis of sensitivity of measuring vertical acceleration (along a vertical), because of integration, there occurs an accumulation error in determining the altitude of the flight being equal to approximately 10 m per every minute of the flight, which is unacceptable as well.
Due to the causes mentioned above determining vertical acceleration is not unreasonable considered to be unstable and is not practically used.
These are objects of the present technical solution to considerably increase the accuracy, accelerate the readiness for operation, and decrease weight, price and sizes.